html-spec/AndMIME.html at master · dckc/html-spec · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
<!DOCTYPE HTML PUBLIC "-//W3O//DTD WWW HTML 2.0//EN">
<HTML>

<HEAD>
<TITLE>HTML and MIME</TITLE> <NEXTID N="z4"></HEAD>

<BODY>

<H1>HTML and MIME</H1>

<P>The definition of the HTML content subtype is

<DL>

<DT>MIME Type name

<DD>text

<DT>MIME subtype name:

<DD>html

<DT>Required parameters:

<DD>none

<DT>Optional parameters:

<DD>level, version, charset
</DL>

<H2>Level</H2>

<P>The level parameter specifies the feature set which is used
in the document. The level is an integer number,
implying that any features of same or lower level may be present
in the document. Levels are defined by this specification.

<H2>Version</H2>

<P>In order to help avoid future compatibility problems,
the version parameter may be used to give the version number
of this specification to which the document conforms.
The version number appears at the front of this document and
within public identifier for the SGML DTD.

<H2>Character sets</H2>

<P>The base character set (the SGML BASESET) for HTML is ISO
8859/1, also known as <EM>Latin alphabet No.
1</EM> or simply <EM>Latin-1</EM> This is the set referred to
by any numeric <A NAME="z3" HREF="Text.html#z4">character references</A>.
The actual character set used in the representation of an HTML
document may be ISO 8859/1, or its 7-bit subset which is ISO
646 (ASCII). There is no obligation for an HTML document to contain
any characters above decimal 127. It is possible that a transport
medium such as electronic mail imposes constraints on the number
of bits in a representation of a document,
though the HTTP access protocol used by W3 always allows 8 bit
transfer.

<P>When an HTML document is encoded using 7-bit characters,
then the mechanisms of <A NAME="z1"
HREF="Text.html#z4">character references</A> and <A
NAME="z2" HREF="Text.html#z5">entity references</A> may be used
to encode characters in the upper half of the ISO 8859/1 Latin-1
set. In this way, documents may be prepared which are suitable
for mailing through 7-bit limited systems.

<H3>Character set option (proposed)</H3>

<P>The SGML declaration specifies ISO 8859/1 Latin alphabet No.
1 as the base character set. The charset parameter is reserved
for future use. Its intended significance is to override the
base character set of the SGML declaration.
Support of character sets other than ISO 8859/1 Latin alphabet
No. 1 is not a requirement for conformance with this specification.
</BODY>
</HTML>